*{margin: 0;padding: 0;}

.banner{width: 700px;margin: 0 auto;height: 393.5px;overflow: hidden;margin-top: 100px;position: relative;}
.banner ul.imgs li{list-style: none;position: absolute;top: 0;left: 0;display: none;}
.banner ul.imgs li:first-child{display: block;}
.banner ul.imgs li a img{width: 700px;vertical-align: middle;}

.banner ul.dots{position: absolute;z-index: 99;left: 284px;bottom: 20px;}
.banner ul.dots li{background: #fff;width: 12px;height: 12px;float: left;list-style: none;border-radius: 50%;margin: 0 5px;cursor: pointer;}
.banner ul.dots li:first-child{background: #f00 !improtant;}